Rhubarb Water

This rhubarb water is not so interesting on it's own, but is amazing as a mixing ingredient for Rhubarb Martinis

2 pounds rhubarb, washed and cut into chunks

4 cups boiling water

3/4 cup sugar

Juice of 1/2 lemon

1. Put the rhubarb in a bowl, pour over 4 cups/1 litre boiling water, cover, and leave at room temperature overnight.
2. Next day, strain the liquid into a saucepan, discarding the rhubarb. Add the sugar and lemon juice, and bring to a boil 5 minutes. Cool. Taste and add more lemon juice if necessary. Strain into a bottle, and cork. Store refrigerated, to be served ice-cold.